1. Field of the Invention
The present invention relates to an electric artificial larynx which is an apparatus used by a person who cannot vocalize owing to an operation for removing the larynx for the reason of laryngeal cancer or the like to vocalize again.
2. Description of the Related Art
When the larynx is removed, the vocal cords which are a sound source for vocalizing are lost. Therefore, a person whose vocal cords have been removed cannot vocalize. However, even when the vocal cords are lost, articulating organs such as the tongue and lips still remain. Therefore, if a sound source can be formed in place of the vocal cords by any means, vocalizing which may be incomplete is possible.
Substitute vocalization means based on this principle include gullet vocalization, operational sound language preservation, electric artificial larynx and the like. The gullet vocalization is that a belch-like air stream is burst forth to make sounds which are changed by the tongue, lips and the like for vocalizing. This gull vocalization does not require an extra device and enables a person having no vocal cords to vocalize freely anywhere once he/she masters this technique. However, the gull vocalization involves such defects that it takes time to master this gull vocalization, it is difficult for a sickly person or aged person to master this and it is impossible to vocalize loud.
An example of the operational sound language preservation includes an artificial vocal organ disclosed by Japanese Patent Application Laid-open No. Hei 6-133993. Since this artificial vocal organ is buried in the body, there is no trouble of carrying an extra device and a person having this artificial vocal organ can vocalize freely anywhere like the gull vocalization. However, the artificial vocal organ requires an extra surgical operation on the trachea and must be exchanged and cleaned every about 8 weeks due to the generation of adherents or bacteria.
The electric artificial larynx forms a substitute sound source in place of the vocal cords mechanically or electromechanically and this substitute sound source is introduced into the oral cavity to enable a person who had an operation for removing the larynx to vocalize. This electrical artificial larynx is used in such a manner that it is pressed against the cervical region of the human body and a switch is operated with a finger when the person wants to vocalize. Therefore, it has such troubles that this device must always be carried and the work of pressing the switch against the cervical region and operating the switch must be carried out every time the person vocalizes.
However, this electrical artificial larynx does not need long-time training like the gull vocalization and can be used by a sickly person and aged person with ease. Unlike the artificial vocal organ, a special surgical operation or regular exchange and washing are not necessary and the electrical artificial larynx is very easy to handle. Since the electrical artificial larynx has such advantages, it is indispensable as substitute vocalization means.
Conventional electrical artificial larynxes have a switch for turning on and off a substitute sound source. A person who had an operation for removing the larynx only turns on and off the substitute sound source by operating this switch with his/her finger to vocalize. It is a well known fact that when a non-handicapped person vocalizes, he/she changes the basic frequency and sound volume of the vocal cords according to the contents of vocalizing to express accent and intonation or change the tone of voice. In contrast to this, it is impossible to express accent and intonation or change the tone of voice with substitute sound sources formed by the conventional electric artificial larynxes because they are a substitute sound source having a fixed basic frequency and a fixed sound volume. As a result, they have a serious problem that the person who had an operation for removing the larynx can vocalize only in an unnatural voice.
The influence that this problem exerts upon the daily life of the person who had an operation for removing the larynx is extremely large. That is, a lot of mental anguish has been complained that he/she cannot be understood what his he/she says, his/her delicate feeling cannot be expressed, it is hard to vocalize over the phone, or vocalizing with another person makes him/her feel ashamed or irritated, or surprises another person because his/her voice is unnatural.
It is needless to say that the basic frequency and sound volume of the vocal cords must be changed to sing a song. However, since the conventional electric artificial larynxes can form only a sound source having a fixed basic frequency and a fixed sound volume as described above, it is impossible to sing a song with the electric artificial larynxes.
To solve the above problems, the applicants jointly developed electric artificial larynxes as disclosed by Japanese Patent Application Laid-open Nos. Hei 7-433 and Hei 8-265891. The electric artificial larynx disclosed by Japanese Laid-open Patent Application No. 7-433 makes it possible to express accent and intonation or change the tone of voice while vocalizing by controlling the basic frequency and sound volume of a substitute sound source output from an acoustic converter according to information on respiration and the like detected by biological information detecting means. Therefore, it is possible to vocalize in a more natural voice.
Information for controlling the basic frequency and sound volume is recorded in an information recording medium in advance so that the basic frequency and sound volume of the substitute sound source output from the acoustic converter can be controlled according to information read from this information recording medium. Therefore, especially when information for controlling the basic frequency and sound volume is predetermined as in the case that words and sentences which are used frequently are vocalized or a song is sung, a great effect is obtained.
Further, the electric artificial larynx disclosed by Japanese Laid-open Patent Application No. 8-265891 comprises a switch for turning on and off a sound produced from an acoustic converter and a unit for changing the basic frequency and volume of the sound which is integrated with the switch. Therefore, operation efficiency is greatly improved, accent and intonation are easily expressed, a more natural voice can be obtained, and the device can be reduced in size and cost.
Since a piezoelectric sounding body or electronic sounding body is used as the acoustic converter, reductions in size and cost are possible and a more natural voice can be obtained due to quick response and a wide frequency band.
Thus, the electric artificial larynxes developed by the applicant solve the problems of the prior art, greatly improve the quality of sound, produce a sound similar to a human voice and enhance convenience.
However, the electric artificial larynxes disclosed by the above publications still have a problem with operation efficiency which is one of the defects of the prior art. That is, all the electric artificial larynxes of the prior art produce a sound by applying a sound source generating unit to the cervical region of an operator and operating a switch for turning on and off the sound source while holding the body with one hand. The body of each of the devices incorporates a control circuit for controlling the sound source generating unit and a power source unit for supplying power to the sound source generating unit in addition to the sound source generating unit and has a total weight of more than 100 g and a length of more than 10 cm.
The body of this electric artificial larynx must be brought up to the cervical region each time an operator wants to vocalize, which is an operation trouble for the operator (a person whose had an operation for removing the larynx). Since the electric artificial larynx must be operated by holding the body with one hand, only the other hand can be used while vocalizing. Therefore, the operator cannot take a memo while talking on the telephone or cannot vocalize when work requiring both hands is carried out with the result that good communication cannot be made, thereby making it difficult for a person who had an operation for removing the larynx to return to the society, which is a serious problem to be solved.
It is an object of the present invention which has been made to solve the above problem to provide an electric artificial larynx which improves operation efficiency by eliminating the trouble of bringing a sound source generating unit up to the cervical region each time an operator vocalizes. It is another object of the present invention to provide an electric artificial larynx which enables an operator to use both hands when vocalizing. It is still another object of the present invention to provide an electric artificial larynx which can reduce the size of a sound source generating unit and does not provide an operator with a feeling of physical disorder when only the sound source generating unit is attached near the cervical region.
According to a first aspect of the present invention, there is provided an electric artificial larynx which comprises a sound source generating unit which is held by interposition means attached directly or indirectly to the human body and can be always placed near the cervical region and a portable controller which is separated from the sound source generating unit and can operate the sound source generating unit. Therefore, only the sound source generating unit can be placed near the cervical region and the controller can be stored in clothes or the like. As a result, it is not necessary to bring the sound source generating unit up to the cervical region by hand each time an operator vocalizes, thereby greatly improving operation efficiency. In addition, the controller is devised to enable the operator to use both hands freely when vocalizing. The interposition means is a band wound round the neck, an accessory covering the vocal cords, a member projecting toward the cervical region from a device attached to the arm or shoulder, or the like.
According to a second aspect of the present invention, there is provided an electric artificial larynx wherein the above controller comprises a control signal generating unit which includes a sensor for detecting biological information or a switch for supplying a signal and a control unit which drives and controls the sound source generating unit in response to a signal from the control signal generating unit and has a power source unit for supplying power to the sound source generating unit. Therefore, the sound source generating unit can be easily controlled by the sensor or the like of the controller and supplied with power by the power source unit of the control unit. The sensor for detecting biological information may be an exhalation sensor for detecting the exhalation of an operator, a muscle potential sensor for detecting the potential of muscle near the mouth portion of an operator, a sensor for detecting the movements of ear holes which are considered as the movements of jaws, a brain wave sensor for detecting changes in brain waves which are considered as the movement of the mouth or the will of vocalizing, or the like.
According to a third aspect of the present invention, there is provided an electric artificial larynx wherein the interposition means is a band wound round the neck and the control signal generating unit is an exhalation sensor for detecting biological information attached to the band. When the sound source generating unit is attached to the band, it can be contacted to the cervical region and can be always placed on the cervical region unless the band comes off from the neck. In addition, as the exhalation sensor can be attached to the band, another device for attaching the sensor is not required, thereby making it possible to reduce the size of the apparatus and easy to handle the apparatus. Further, since the exhalation sensor can be attached to the band, both hands are free and can be used to do other work while vocalizing.
According to a fourth aspect of the present invention, there is provided an electric artificial larynx wherein the control signal generating unit comprises a pressure switch fixed to a finger sack and a pressure sensor which is operated by this pressure switch. Since the pressure sensor is operated by the pressure switch fixed to the finger sack, the sound source generating unit can be controlled by slight changes in the pressure of a finger. Therefore, the sound source generating unit can be controlled while other work, for example, carrying a book or reading a book can be continued with a hand having the finger sack.
According to a fifth aspect of the present invention, there is provided an electric artificial larynx which comprises a sound source generating unit for generating a sound source by opposing a vibration sheet to a shaft which operates together with the coil of a voice coil motor and butting this shaft against the vibration sheet intermittently and a controller for controlling this sound source generating unit, wherein the shaft or the coil is supported by an elastic member both ends or peripheral end of which is fixed to the yoke of the voice coil motor, and at least the coil and a coil holder are stored in the yoke. In this invention, the weight of the apparatus can be reduced by using the voice coil motor, rubber supporting the shaft or coil is fixed to the yoke, and at least the coil and the coil holder are stored in the yoke, thereby making it possible to flatten the yoke without increasing the thickness thereof. As a result, even when the sound source generating unit is always placed near the cervical region, it does not give an operator a feeling of physical disorder. As the elastic member is used rubber, sheet spring, resin having elasticity or the like.
According to a sixth aspect of the present invention, there is provided an electric artificial larynx which comprises a sound source generating unit for generating a sound source by opposing a vibration sheet to a shaft which operates together with the coil of a voice coil motor and butting this shaft against the vibration sheet intermittently and a controller for controlling this sound source generating unit, wherein the sound source generating unit is installed such that it can contact the cervical region, and the controller is separated from the sound source generating unit and can be stored in part of clothing covering the human body. Therefore, only the sound source generating unit whose weight has been reduced can be always placed on the cervical region. As a result, the trouble of bringing the sound source generating unit up to the cervical region each time an operator vocalizes is eliminated, thereby improving operation efficiency. Since the heavy controller can be stored in part of clothes, only the small-sized sound source generating unit can be seen, which greatly reduces a third person""s feeling of difference. The clothing material may be clothes such as a business suit, trousers, coat, blouse or slacks, pouch to be put on the waist, small bag to be hung from the shoulder, hat to be put on the head, or the like.
According to a seventh aspect of the present invention, there is provided an electric artificial larynx which comprises a sound source generating unit for generating a sound source by opposing a vibration sheet to a shaft which operates together with the coil of a voice coil motor and butting this shaft against the vibration sheet intermittently and a controller for controlling this sound source generating unit, wherein the sound source generating unit is separated from the controller, and the thickness of the sound source generating unit is set to 5 to 15 mm. Therefore, the sound source generating unit can be made light in weight and small in size, thereby making it possible to place it always on the cervical region. As a result, the trouble of bringing the sound source generating unit to the cervical region each time an operator vocalizes is eliminated, thereby improving operation efficiency. Since the thickness of the sound source generating unit is 5 to 15 mm, it does not project too much even when it is placed near the cervical region, which does not give an operator or a third person a feeling of difference.
According to an eighth aspect of the present invention, there is provided an electric artificial larynx wherein the controller has a power source for driving a voice coil motor. Therefore, the power source for control can be shared by the sound source generating unit.
According to a ninth aspect of the present invention, there is provided an electric artificial larynx wherein the sound source generating unit is attached to interposition means fixed to the human body or a clothing material covering the human body and can be moved in a predetermined direction based on the interposition means when or right before a sound is produced from the sound source generating unit. Therefore, while the sound source generating unit is attached to the interposition means, it is not contacted to the cervical region but can be contacted to the cervical region only at the time of vocalizing. As a result, when an operator is silent, he/she does not feel the application of the sound source generating unit on the cervical region and feels free from the application.
According to a tenth aspect of the present invention, there is provided an electric artificial larynx wherein the control of the sound source generating unit by the controller is carried out wireless and the supply of power to the sound source generating unit is carried out by a power source placed in a portion other than the controller. Since the sound source generating unit is controlled wireless, a control lead wire for connecting the sound source generating unit to the controller is not required, thereby making it possible to increase the freedom of installing the controller. For example, the power source of the power source generating unit is stored in a pouch put on the waist and the controller is shaped like a wristwatch or mechanical pen so that it can be placed around an exhalation sensor.
According to an eleventh aspect of the present invention, there is provided an electric artificial larynx which has a controller for causing the sound source generating unit to output a sound using sound source data based on the voice data of an operator before an operation for removing the larynx. Since the output sound is based on the voice data of the operator before the operation, he/she can vocalize infinitely in a voice similar to his/her own voice before the operation.
According to a twelfth aspect of the present invention, there is provided an electric artificial larynx which comprises a controller having sound source data based on the voice data of an operator before an operation for removing the larynx and a sound source generating unit for outputting a sound using the sound source data. The voice data of the operator before the operation is stored in the control unit, thereby making it possible for the operator to vocalize in a voice similar to his/her own voice before the operation.
According to a thirteenth aspect of the present invention, there is provided an electric artificial larynx which comprises a sound source generating unit in place of the vocal cords and a controller for operating the sound source generating unit, wherein memory means for storing sound source data for singing a song is provided in the controller detachably. Therefore, an unlimited number of songs can be sung theoretically by storing many songs in many storage means.